Processing continues for the second space shuttle mission in the Return to Flight sequence. Wire inspections and chafe protection installation continue on the reaction jet driver. The nose landing gear was cycled Thursday to support tile work on the shuttle’s heat shield.

The Orbiter Boom Sensor System is in the transfer aisle of the processing facility awaiting installation. The boom installation was moved to next week to allow for final work on the pedestals and latches.

Technicians are removing and replacing approximately 100 gap fillers daily in a main priority area. This work is being performed due to two gap fillers that were protruding from the underside of Discovery during the last mission, STS-114. New installation procedures are being developed to ensure gap fillers stay in place and do not pose any hazard during the shuttle’s re-entry to the atmosphere.

Engineers are evaluating data from two catch bottles that indicated higher levels of oxygen than expected in the shuttle’s aft compartment during the last mission. Six bottles automatically capture samples for two seconds in pairs at precise times after launch and through the first two minutes of flight.

The higher readings have been categorized as a formal in-flight anomaly, but they could be an analysis mistake. During Discovery’s launch, all three main engines performed normally, which indicated there wasn’t a significant oxygen leak in the aft compartment. Engine performance and the catch bottles are the only way to detect in-flight leaks.

Technicians continue processing this mission to the International Space Station. Preparations are under way to drain Freon coolant loop No. 1 in support of a cold plate removal and replacement. The forward reaction control system was installed on Tuesday. This control system sits behind the nose cap and provides the thrust for rotational maneuvers and small velocity changes along the orbiter axis.

Endeavour (OV-105)

In Orbiter Processing Facility Bay 2, technicians continue processing after a nearly two-year major modification period. Body flap preparations are nearing completion, and installation is scheduled for late next week. Installation of water spray boilers No. 1 and 2 continues; work is focused on the safety wiring.

Wiring for the new external fuel tank digital camera continued. The vehicle will remain powered down for work on a new modification called the “station to shuttle power transfer system.” The new system will allow the vehicle to stay docked to the International Space Station longer than during previous missions.